Torque-applying tool for button-head concrete wall form tie rods

ABSTRACT

A torque-applying tool by means of which the frangible protruding ends of concrete wall form tie rods with conventional button-heads and breakbacks may be twisted from the embedded medial regions thereof. An eccentric jaw action is effective in the direction of torque-application to afford a high mechanical advantage for tie rod clamping, coupled with high torque leverage, while a spring-biasing action, coupled with an overlay flange on the clamping jaw permits one-hand manipulation of the tool.

United States Patent Eriltsson [is] 3,651,835 [4 1 Mar. 28, 1972 TORQUE-APPLYING TOOL FOR BUTTON-HEAD CONCRETE WALL FORM TIE RODS Inventor: George J. Erlksson, Morton Grove, lllr Assignee: Superior Concrete Accessorles, lnc.,

Franklin Park, lll.

Filed: Aug. 17, 1970 Appl. No.: 64,212

US. Cl ..l40/l49, 225/102 Int. Cl. ..B2lf 7/00 Field of Search 140/149; 225/102 6 Renew M UNITED STATES PATENTS 2,733,736 2/l956 McLaughlin ..l40/l49 Primary Examiner-Lowell A. Larson Attorney-Norman H. Gerlach ABSTRACT A torque-applying tool by means of which the frangible protruding ends of concrete wall form tie rods with conventional button-heads and breakbacks may be twisted from the embeddedmedial regions thereof. An eccentric jaw action is effective in the direction of torque-application to afford a high mechanical advantage for tie rod clamping, coupled with high torque leverage, while a spring-biasing action, coupled with an overlay flange on the clamping jaw permits one-hand manipulation of the tool.

12 Claims, 8 Drawing Figures -SSLBSS P'ATENTED MAR 2 8 I972 SHEET 1 UF 3 Jaw clamping IN VE N TOR GEORGE J. ER/KSSON Airy.

PATENTED ma 2 8 m2 SHEET 2 [1F 3 IN VE IV TOR. GEORG/ziR/KSSON AH y.

TORQUE-APPLYING TOOL FOR BUTTON-HEAD CONCRETE WALL FORM TIE RODS The present invention relates generally to torque-applying tools of the type which is adapted for use in connection with the fracturing of concrete wall form tie rods bya twisting action which is exerted upon the protruding ends of concreteembedded tie rods in order to wrest such ends from the medial portions of the tie rods which remain embedded in the formed concrete walls after the wall form sides have been stripped from the walls. More specifically, the torque-applying tool that constitutes this invention is designed for cooperation with the enlarged button-like heads which are provided on the end extremities of cylindrical tie rods and, by reason of their presence on the tie rods, have caused such tie rods to be given the designation button-head tie rods" throughout the concrete forming industry.

The torque-applying tool of the present invention is designed as an improvement upon the tool which is shown and described in my copending US. Pat. application, Ser. No. 841,043, filed on July 11, 1969 and entitled TORQUE-AP- PLYING TOOL FOR CONCRETE WALL FORM TIE RODS," now abandoned, both tools being designed for the same purpose and being generally similar in their structural design, as well asin their mode of operation. However, the present torque-applying tool possesses several features of advantage over the tool of the aforementioned patent application, as well as extending the usefulness of such tool by obviating certain limitations that are attendant upon the construction and use of the earlier tool.

Principal among these limitations is the fact that the earlier tool ordinarily requires the use of both hands for its manipulation and thus leaves the operator in an unstable position, particularly when he is operating the tool while standing on a scaffold or ladder. Additionally, there is a possibility that with the earlier tool, a secure clamping grip on the tie rod buttonhead may not be attained by the torque-applying jaws of the tool at the time that actual torque-application is made. The jaws of the earlier tool are thus capable of slipping out of engagement with the tie rod with the resultant possibility of the operator losing his balance on the scaffold or ladder or other- A wise suffering damage or injury.

Torque-applying tool of the present invention is designed to overcome the above-noted limitations that are attendant upon the construction and use of the earlier tool and, accordingly, the invention contemplates the provision of a tool wherein when its torque-applying jaws are initially applied to a particular tie rod, a firm grip upon the tie rod button-head must necessarily be attained. Otherwise, the operating lever-like handles which are associated with and form parts of the tool and control the jaw-closing movements cannot be moved and the operator will be apprised of the fact that the tool is not in operative register with the tie rod.

An additional limitation that is attendant upon the construction and use of the earlier tool resides in the fact that the operator is required to use both hands not only in manipulating the tool to exert jaw pressure on the tie rod button-head, but also in swinging the tool about the axis of the tie rod for torque-application purposes. In addition, the operator is required to use both hands to bring the tool to its open jaw position so that it may initially receive the button-head in position between the jaws. This requires the operator to assume an initial position on the scaffold or ladder which is compatible with proper guiding of the tool into operative position, and also to maintain this same position without appreciable change during jaw-closing and tool-rotating or turning operations. The present torque-applying tool also obviates this last mentioned limitation in that the clamping jaws, as well as the handles which control their movements, are spring-biased in a jaw-closing direction and, furthermore, the jaw-actuating handles are so designed that when they are moved to their full jaw-opening position they are in close proximity to each other and the operatoris able to grasp them both with the fingers of one hand so that he may then bring the tool to its initial position of operative register with the tie rod button-head while using the other hand to preserve his position on the scaffold or other supporting means, after which he may relax his grip on the tool handles with the assurance that the spring-biasing action of the tool jaws and handles will maintain the tool caphired by the tie rod. Thereafter, the operator may, if he so desires, completely release the tool leaving it hanging, so to speak, on the tie rod and assume a more propitious position on the scaffold which will enable him further to manipulate the tool for torque-applying purposes. Still further, the present tool is not only spring-biased in the manner briefly outlined above, but it also is self-energizing in that after the clamping jaws have been caused initially to engage the button-head therebetween, the application of a torque-applying leverage to one of the two lever-like handles will increase the binding action of the jaws upon the button-head, the greater the pressure on the handle the greater will be the jaw-clamping pressure. Thus, only one handle is required for torque application by the tool to the tie rod and this, of course, may be accomplished by the operator with the use of either one or two hands upon such one handle, the other handle being used only at such time as it is necessary to open the clamping jaws either for initial engagement of the button-head by the tool or for release of the button-head after the adjacent protruding end of the tie rod has been broken away from the concrete-embedded medial portion of the tie rod.

The provision of a torque-applying tool of the character briefly outlined above and possessing the stated advantages being the principal object of the present invention, numerous other objects and advantages will readily suggest themselves as the nature of the invention is better understood from a consideration of the following detailed description.

The invention consists in the several novel features which are hereinafter set forth and are more particularly defined by the claims at the conclusion hereof.

In the accompanying three sheets of drawings forming a part of this specification or disclosure, one illustrative embodiment of the invention is shown.

In these drawings:

FIG. 1 is a perspective view of the improved torque-applying tool of the present invention, such tool being shown operatively poised or positioned with respect to the adjacent protruding end of a concrete embedded tie rod preparatory to engaging the same for twisting purposes;

FIG. 2 is a perspective view similar to FIG. 1 but showing the tool operatively applied to and captured by the adjacent button-head of the tie rod preparatory to the application of torque to the tool for tie rod fracturing purposes;

FIG. 3 is a perspective view similar to FIGS. 1 and 2 but illustrating the position of the tool at the time of tie rod fracture;

FIG. 4 is a front elevational view of the tool in its free state;

FIG. 5 is a side view of the tool;

FIG. 6 is a rear view of the tool;

FIG. 7 is a fragmentary side elevational view of the tool with the tie rod engaging jaws in their fully open tie rod receiving position and with certain parts broken away in the interests of clarity; and

FIG. 8 is an exploded perspective view of the various constituent parts of the tool.

Referring now to the drawings in detail, and in particular to FIGS. 1, 2, 3, 4 and 6, a torque-applying tool according to the present invention is designated in its entirety by the reference numeral 10 and involves in its general organization a twopiece body 12 which is formed of separate or independent sections 14 and 16 (see also FIG. 8). The two-piece body 12, in the free condition of the tool as illustrated in FIG. 4, defines a flattened tubular structure presenting side walls 18 and 20, a curved split top wall 22 (see FIG. 5), a split bottom wall 24, and open front and rear ends. The side wall 18 forms a part of the body section 14 and the side wall 20 forms a part of the body section 16. The details of the aforementioned walls 18, 20, 22 and 24 which define the aforementioned flattened tubular structure (two-piece body 12) are best illustrated in FIGS. 3 and 4. The two body sections 14 and 16 are held together in assembled relation by means of a clamping bolt 25 which passes through a smooth circular hole in the side wall 20 of the body section 16 and is threadedly received in a threaded hole in the side wall 18 of the body section 14.

The front regions of the side walls 18 and 20 are recessed as best shown in FIG. 4 so as to provide an upwardly facing pocket 26 (see FIGS. and 7) which establishes a horizontal ledge 27 on which there is supported a block-like jaw 28. The latter is preferably formed of hardened steel. It is loosely enclosed within the aforementioned pocket 26 and is held against upward displacement by cooperating or interlocking shoulders 30 (see FIG. 7) on the rear side of the jaw 28 and certain front portions of the side walls 18 and 20 of the tool body 12. The jaw 28 is generally in the form of a cube except for the provision of a pair of upwardly extending relatively sharp ridges or teeth 32 on the upper part of the jaw. Said jaw 28 constitutes one, of two tie-rod clamping jaws for the tool and, although said jaw 28 is fixed with respect to the tool body 12, it and its encompassing tool body are, during the use of the tool, caused to swing about the axis of a torque-applying shaft 38 which embodies at one end thereof a fixed jaw 40. For descriptive purposes herein, the jaw 28 will be considered as the bodily movable jaw of the tool. This movable jaw 28 is designed for engagement with the button-head on the adjacent end of a tie rod when the tool is in actual operation as will be described in detail subsequently.

The jaw 40 of the torque-applying tool may be considered the fixed jaw of the tool and is in the form of a knurled head of generally cylindrical configuration, the knurling being sharply cut so that said jaw has good frictional characteristics when it is in engagement with the button-head on the adjacent protruding end of the tie rod during operation of the tool. The jaw 40 is integrally formed on the torque-applying shaft 38 and the latter seats in a pair of opposed complementary semicylindrical recesses 44 (see FIG. 8). Said recesses are formed internally on portions of the side walls 18 and of the tool body 12 and constitute bearing surfaces for rotation of the tool body as a whole about the axis of the torque-applying shaft 38. The jaw 40 is provided with a recess 46 (see FIGS. 4, 5, 7 and 8) of approximately 90 arcuate extent along its forward end region, this recess afiording a clearance region for initial entry of the button-head on the end of a tie rod into position between the movable and fixed jaws 28 and 40, as will be set forth in detail presently, the remaining major circle sector of the jaw 40 constituting a fixed tie rod-engaging jaw.

The generally cylindrical fixed jaw 40 is eccentrically disposed on the torque-applying shaft 42, the axis of the jaw being slightly offset with respect to the axis of the shaft as best shown in FIGS. 3 and 5 of the drawings. The forward end of the torque-applying shaft is provided with a tie rod retaining flange 52 which, in effect, constitutes a rim flange on the forward end of the shaft 42. The retaining flange 52 is cylindrical except for the provision of a notch 54 in the periphery thereof. Said notch 54 is on the order of 90 in extent, is in circumferential register with the recess 46, and constitutes a clearance space to permit entry of the button-head on the adjacent protruding end of the tie rod into position between the two clamping jaws 28 and 40.

The end of the torque shaft remote from the fixed jaw 40 is bifurcated as indicated at 56 (see FIGS. 3, 6 and 7), the furcations straddling the opposite sides of the shank portion 58 of a main lever-like torque-applying handle 60, the latter being provided with a hand grip 62. A set screw 63 passes through one of the furcations of the torque-applying shaft 42 and anchors the shank 58 in position. The shank portion 58 of the handle 60 is provided with a laterally turned priximal end region which constitutes a limit stop 64 in that it normally engages the side wall 18 of the tool body 12 (see FIG. 3) and limits the extent of one direction angular movement of which the tool body is capable. When the limit stop 64 is in engagement with the side wall 18 of the tool body 12, the movable jaw 28 and the fixed jaw 40 are in their fully open position with the two jaws being widely separated to such an extent that the button-head on the adjacent protruding end of the tie rod may be received between these two jaws. The two jaws 28 and 40 are normally maintained in their fully open position as shown in FIG. 4 by means of a helical torsion spring 66 which surrounds the torque-applying shaft 38 and is interposed between the handle shank portion 58 and the rear end face of the tool body. One end of the spring 66 is turned laterally as indicated at 68 in FIGS. 5 and 7 and projects into a small bore 70 in the shank 58 of the handle 60. The other end of the spring encircles a clamping bolt 72 which enters the tool body through a pair of registering recesses 73 (see FIG. 8), this latter bolt also serving the purpose of anchoring a secondary jaw-control handle 76 in a fixed position on the tool body 12 as shown in FIG. 5. This secondary jaw-control handle 76 projects into the tool body through the bottom wall 24, the two sections 14 and 16 of the tool body being provided with registering complementary recesses 78 (see FIGS. 1 and 3) to thus admit said handle 76. The latter is provided with a laterally offset portion 79 (see FIGS. 1 and 3) which closely parallels the hand grip 62 of the torque-applying handle 60 when the two jaws 28 and 40 are in their fully open position. By reason of this offset portion 79, the operator or user of the tool 10 is able to grasp both handles 76 and 60 with the fingers of one hand when initially guiding the tool into its tie rod-engaging position, thus maintaining the tie rod receiving jaws 28 and 40 in their fully open position, all in a manner that will be set forth in detail when the operation of the tool is set forth.

In order to prevent dislodgment of the adjacent protruding tie rod end from the working jaw area of the tool when the tool is at rest in a hanging position on the tie rod during a change in position of the operator on a scaffold or the like in between the time he initially applies the tool to a given tie rod and the time he actually applied torque to the tie rod, an L-shaped retention plate 80 is maintained in position against the side wall 20 of the body section 16 by the aforementioned clamping bolt 25 (see FIGS. 1, 3 and 5) and is provided with a laterally turned end portion 81 which extends across the open front end of the tool body 12 and is formed with a notch 82 in one edge thereof in order to admit the enlarged button-head of the adjacent protruding end of the tie rod during initial application of the tool to the latter.

As set forth previously, the torque-applying tool 10 is adapted for use in connection with the application of torque to the adjacent protruding end of a tie rod, the medial region or portion of which is embedded in a concrete wall after the wall has been formed in a conventional manner by first pouring wet concrete between the two opposed spaced apart sides of a concrete wall form and then allowing the concrete to become hardened in order to produce the completed wall. Such a tie rod is shown in FIGS. 1 and 2. It is designated by the reference numeral 83 and the presence of a concrete wall is implied by the bracket which indicates that the medial portion 84 of the tie rod is embedded in a concrete wall. The illustrated protruding or free end portion 86 of the tie rod 83 is joined to the medial portion 84 by a conventional breakback 88 which weakens the metal of the tie rod and thus determines the point of breakoff. Radial fins 90 are provided on the medial tie rod portion 84 and prevent the embedded medial portion 84 of the tie rod from turning within the hardened concrete wall when torque is applied to the illustrated protruding end portion 86 for the purpose of twisting the said end portion from the embedded medial portion so that it may be removed from the wall. The tie rod 82 is conventional and the illustrated protruding end portion 86 is provided with the usual enlarged button-head 92 which cooperates with various items of concrete wall fonn hardware such as a waler bracket or the like.

The component parts of the tool 10 are so designed and arranged that angular displacement of the secondary jaw-control handle 76 throughout an angle of approximately with respect to the axis of the torque-applying handle 60 will serve to move the jaws 28 and 40 between their fully closed and their fullyopen positions. The former position is illustrated in FIG. 4, while the latter position is illustrated in FIG. 1. It is to be noted at this point that the herein described fully closed" position is the normal position of the tool in its free state and that actually the two jaws 28 and it) are not in contact with each other, but instead, remain spaced apart a distance which is somewhat less than the diameter of the button-head 92. The "fully open position of the jaws is the position which is represented in FIG. 1 wherein the two jaws 28 and 40 are widely spaced apart, i.e., they assume positions wherein the distance between them is somewhat greater than the diameter of the button-head 92.

In the operation of the torque-applying tool 110, the operator will grasp the torque-applying handle 60 with one hand and the secondary jaw-control handle 76 with the other hand and swing the latter into parallelism with the former to the end that the two handles will then be in close proximity to each other. Thereafter, the operator may seize both handles with the fingers of one hand as shown in FIG. I and withdraw his other hand. At the conclusion of the last-mentioned operation, the operator, utilizing only one hand, will align the jaw area of the tool with the axis of the tie rod 82 and cause such jaw area to address the tool as shown in FIG. 11. Immediately thereafter, the operator will advance the tool upon the adjacent protruding end portions 86 of the tie rod 83 so that the button-head 92 enters the jaw area and lies between the two clamping jaws 28 and 40 as shown in dotted lines in FIG. 1, and in full lines in FIG. 2. Thereafter, the operator will release the jaw control handle 76 while maintaining his grip upon the torque-applying handle 60 and the torsional force of the torsion spring 66 will swing the entire tool body 112 and its fixedly secured handle 76 in a clockwise position as illustrated by the arrow in FIG. 1, thus causing the side wall of the tool body 12 to engage the button-head 92 and displace the tool body so that the jaw 28 will shift circumferentially about the axis of the torque-applying shaft 38 in order that the botton-head will move out of the recess 46 and assume a position against the knurled jaw 40. During this swinging movement of the secondary jaw control handle 76 and the tool body 12, the jaw 28 will progressively move closer to the knurled jaw 40 until such time as the button-head 92 is firmly engaged between the two jaws. Depending upon the diameter of the button-head 92, the angular position of the handle 76 with respect to the torque-applying handle 60 will vary. In an instance where the tie rod has a buttonhead, the diameter of which is on the order of one-half inch, the handle 76 will come to rest at a position wherein it extends at an angle of approximately 90 with respect to the axis of the handle 60 as shown in dotted lines in FIG. l, and full lines in FIG. 2.

It is to be noted that at this time the tie rod retaining flange 52 on the extreme end of the knurled jaw 40 will have moved in front of the working area of the tool and behind the buttonhead as shown in FIG. 2, thus positively preventing the buttonhead from slipping from between the two jaws 28 and 60. At the same time, the cylindrical portion of the adjacent protruding tie rod end portion 86 will remain nested within the notch 82 in the laterally turned end portion 81 of the L-shaped retention plate 80, and in combination with the periphery of the flange 52, capture the adjacent protruding tie rod end portion 86 so that the operator may now completely release the tool 10 if he so desires in order that he may change his position on the scaffold or ladder preparatory to applying manual torque to the tool for tie rod twisting purposes. The tool will thus remain in position on the tie rod until such time as it is engaged by the operator for torque-application purposes.

Twisting of the tie rod for fracture purposes is accomplished by the simple expedient of manually swinging the torque-applying handle 60 in a clockwise direction as seen in FIG. 2. During such swinging movement, the torsion which is applied by the spring 64 will bias the tool body 12 in a jaw-closing position so that the jaws will not slip circumferentially on the button-head 92. Furthermore, the resistance which is offered by the tie rod itself to swinging movement of the tool body 12 will act progressively to increase the binding action of the two jaws, the jaw 28 being thus self-energizing with respect to the jaw 40.

Fracture of the tie rod at the breakbaclc point 88 will occur under the influence of varying degrees of circumferential displacement between the concrete-embedded medial tie rod portion 84 and the adjacent free or protruding end portion 86 depending upon the physical character of the tie rod. In FIG. 3, complete fracture of the tie rod and dislodgment of the end portion 86 are shown as taking place at such time as the tool body 12 has been rotated from the position wherein it is shown in FIG. 2 through an angle of approximately 270 to the position illustrated in FIG. 3. During such rotation of the tool, the jaws 28 and 418 will continue to bind against the button-head 92, and after the fracture occurs, the end portion 86 of the tie rod will remain captured by the tool.

Release of the fractured tie rod end portion 86 from the tool is accomplished by rotating the secondary jaw-control handle 76 in a clockwise direction as viewed in FIG. 3 until such time as the recess 58 in the tie rod retaining flange 52 moves into register with the notch 82 in the L-shaped retention plate 88. At this time, the two jaws 28 and will have moved apart to release the button-head 92 so that the fractured tie rod end portion 86 may be pulled axially from the working area of the tool.

It is to be noted that since the jaw 28 is confined within the tool body 12 solely by the L-shaped retention plate 80 and its clamping bolt 25, it is possible, in the event of wear of the teeth 32, to replace the jaw by removing the bolt 25 and the plate 88 and then applying a new jaw 28.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention. Therefore, only insofar as the invention is particularly pointed out in the accompanying claims is the same to be limited.

Having thus described the invention what I claim as new and desire to secure by letters patent is:

l. A tool for twisting the protruding free end portion of a concrete wall form tie rod from the concrete-embedded medial portion by the application of torque to an enlargement which is provided on the distal end of such portion, said tool comprising a torque shaft having at one end thereof an eccentrically disposed offset arcuate surface which is in the form of a major circle sector and constitutes a fixed tie rod engaging jaw, a main torque-applying handle on said shaft, a tool body mounted on said shaft for swinging movement in opposite directions about the axis of the shaft, a second tie rod-engaging jaw on said tool body and disposed alongside of said fixed jaw, said tool body being capable of swinging movement between a retracted position wherein said second jaw is remote from said fixed jaw and an advanced position wherein said second jaw is in close proximity to said fixed jaw, and a jaw control handle fixedly mounted on the tool body, said arcuate surface being out of radial register with the second tie rod-engaging jaw when the tool body is in its retracted position and being in such radial register when the tool body is in its advanced position.

2. A tool as set forth in claim 1 and wherein said torque shaft is provided with a generally cylindrical eccentrically disposed knurled head, the knurling of which constitutes said fixed tie rod-engaging jaw, and the portion of the head remote from said knurling is recessed to provide a clearance region for entry of the free end portion of the tie rod between the second jaw and the knurled head when the tool body is in its retracted position.

3. A tool as set forth in claim 1 and wherein the recessed portion of the head defines a limit stop shoulder which is engageable with the enlargement on the free end portion of the tie rod and maintains such enlargement in radial register with both jaws when the enlargement is disposed therebetween.

4. A tool as set forth in claim 1 and including, additionally, a peripheral retaining flange on said fixed jaw which overhangs said arcuate surface so as to lie behind the enlargement on the free end portion of the tie rod when the tool body is in its advanced position.

5. A tool as set forth in claim 4 and wherein said flange is likewise recessed to provide a second clearance region in circumferential register with said clearance region in the head for entry of the free end section of the tie rod between the second jaw and the knurled head.

6. A tool as set forth in claim 5 and wherein said tool body is provided with a pair of side walls between which the enlargement on the protruding free end region of the tie rod is adapted to extend when the latter is projected between said second jaw and the knurled head, said side walls being engageable with said enlargement during swinging movement of the tool body to shift the tool body and move the enlargement and arcuate surface into and out of radial register.

7. A tool as set forth in claim 6 and including, additionally, a retention plate which is mounted on said tool body and is adapted to lie behind the enlargement on the free end portion of the tie rod and, in combination with said retaining flange, maintain the enlargement in position between the second jaw and the knurled head.

8. A tool as set forth in claim 7 and including, additionally, spring means yieldingly biasing said tool body to its advanced position,

9. A tool as set forth in claim 8 and wherein said main torque-applying handle and said jaw control handle extend in the same direction and assume positions of close proximity to each other when said tool body is in its retracted position to the end that both handles may be grasped by an operator in the fingers of one hand.

10. A tool as set forth in claim 9, wherein said retention plate is provided with a notch which is adapted to straddle the free end section of the tie rod and assist said side walls in shifting the tool body during swinging movement of the latter.

11. A tool as set forth in claim 10, wherein said tool body is of open-ended tubular construction, said side walls are substantially flat and parallel and are connected together by a top wall and a bottom wall, the second tie rod-engaging jaw is in the form of a replaceable hardened steel jaw block having tie rod-engaging ridges thereon, resting on said bottom wall, being confined between said side walls, and being maintained in its confined position by said retention plate.

12. A tool as set forth in claim 11 including, additionally, interengaging means on said fixed torque shaft and the tool body for limiting the extent of swinging movement of the tool body on the torque shaft and thus determining the advanced position of the tool body and, consequently, the minimum distance between said jaws. 

1. A tool for twisting the protruding free end portion of a concrete wall form tie rod from the concrete-embedded medial portion by the application of torque to an enlargement which is provided on the distal end of such portion, said tool comprising a torque shaft having at one end thereof an eccentrically disposed offset arcuate surface which is in the form of a major circle sector and constitutes a fixed tie rod engaging jaw, a main torque-applying handle on said shaft, a tool body mounted on said shaft for swinging movement in opposite directions about the axis of the shaft, a second tie rod-engaging jaw on said tool body and disposed alongside of said fixed jaw, said tool body being capable of swinging movement between a retracted position wherein said second jaw is remote from said fixed jaw and an advanced position wherein said second jaw is in close proximity to said fixed jaw, and a jaw control handle fixedly mounted on the tool body, said arcuate surface being out of radial register with the second tie rod-engaging jaw when the tool body is in its retracted position and being in such radial register when the tool body is in its advanced position.
 2. A tool as set forth in claim 1 and wherein said torque shaft is provided with a generally cylindrical eccentrically disposed knurled head, the knurling of which constitutes said fixed tie rod-engaging jaw, and the portion of the head remote from said knurling is recessed to provide a clearance region for entry of the free end portion of the tie rod between the second jaw and the knurled head when the tool body is in its retracted position.
 3. A tool as set forth in claim 1 and wherein the recessed portion of the head defines a limit stop shoulder which is engageable with the enlargement on the free end portion of the tie rod and maintains such enlargement in radial register with both jaws when the enlargement is disposed therebetween.
 4. A tool as set forth in claim 1 and including, additionally, a peripheral retaining flange on said fixed jaw which overhangs said arcuate surface so as to lie behind the enlargement on the free end portion of the tie rod when the tool body is in its advanced position.
 5. A tool as set forth in claim 4 and wherein said flange is likewise recessed to provide a second clearance region in circumferential register with said clearance region in the head for entry of the free end section of the tie rod between the second jaw and the knurled head.
 6. A tool as set forth in claim 5 and wherein said tool body is provided with a pair of side walls between which the enlargement on the protruding free end region of the tie rod is adapted to extend when the latter is projected between said second jaw and the knurled head, said side walls being engageable with said enlargement during swinging movement of the tool body to shift the tool body and move the enlargement and arcuate surface into and out of radial register.
 7. A tool as set forth in claim 6 and including, additionally, a retention plate which is mounted oN said tool body and is adapted to lie behind the enlargement on the free end portion of the tie rod and, in combination with said retaining flange, maintain the enlargement in position between the second jaw and the knurled head.
 8. A tool as set forth in claim 7 and including, additionally, spring means yieldingly biasing said tool body to its advanced position.
 9. A tool as set forth in claim 8 and wherein said main torque-applying handle and said jaw control handle extend in the same direction and assume positions of close proximity to each other when said tool body is in its retracted position to the end that both handles may be grasped by an operator in the fingers of one hand.
 10. A tool as set forth in claim 9, wherein said retention plate is provided with a notch which is adapted to straddle the free end section of the tie rod and assist said side walls in shifting the tool body during swinging movement of the latter.
 11. A tool as set forth in claim 10, wherein said tool body is of open-ended tubular construction, said side walls are substantially flat and parallel and are connected together by a top wall and a bottom wall, the second tie rod-engaging jaw is in the form of a replaceable hardened steel jaw block having tie rod-engaging ridges thereon, resting on said bottom wall, being confined between said side walls, and being maintained in its confined position by said retention plate.
 12. A tool as set forth in claim 11 including, additionally, interengaging means on said fixed torque shaft and the tool body for limiting the extent of swinging movement of the tool body on the torque shaft and thus determining the advanced position of the tool body and, consequently, the minimum distance between said jaws. 